Hello,

I have a requirement when adding Opportunity Line Items to an opportunity to pre-populate some of the fields when the opportunity line item screen opens.  I've been looking into this and I came across some posts detailing how certain Salesforce standard pages can have fields pre-populated by providing URL parameters when opening the page.

http://writeforce.blogspot.co.uk/2013/01/prepopulating-fields-using-url-hacking.html
https://success.salesforce.com/answers?id=90630000000ghPqAAI
http://blog.wdcigroup.net/2013/10/salesforce-pre-populate-form-data-in-create-screen/

What I'm not sure of though is if this can be applied when adding opportunity Line Items as the process to do so involves a number of steps.
- Select the opportunity
- Click on Add Business Line Item button
- On this page select the price book if not alreadty selected,  or if already selected click on the product to add to the Opportunity
- On the next page that opens, this is the page I need to prepopulate a field on.   I presume though lots of other fields/parameters have been set though via the previous steps.   The current pageI am on is https://cs17.salesforce.com/oppitm/multilineitem.jsp
Are there parameters I can specifically pass in the URL to this https://cs17.salesforce.com/oppitm/multilineitem.jsp page?  I tried to pass parameters as follows  
https://cs17.salesforce.com/oppitm/multilineitem.jsp?CF00Ng0000000fk1W01uw000000Vntx8=a2Ng00000004snuEAA  but I get an error "Unable to Access Page".
The paraemter I provided "CF00Ng0000000fk1W01uw000000Vntx8"  I obtained as the ID of the field I wish to pre-populate.

Should this be possible what I am trying to do, or is pre-population of fields only possible for cerrain Standard pages?

Any help on this would be very much appreciated.

Thanking you in advance.